Melt spinning apparatus



March l2, 1963 R. s. BLEY 3,080,607

v MELT SPINNING APPARATUS Filed Jan. 28, 1957 4 Sheets-Sheet 1 '.INVENTOR March 12, 1963 R. s. BLEY NELT SPINNING APPARATUS INVENTOR i 4 Sheets-Sheet 2 Flled Jan 28l 1957 March 12, 1963 R. s. BLEY 3,080,607

MELT SPINNING APPARATUS Filed Jan. 28. 1957 4 Sheets-Sheet 3 INVENT OR March 12, 1963 R. s. BLEY 3,080,607

MELT SPINNING APPARATUS Filed Jan. 28, 1957 4 sheets-sheet 4 1N VENTOR 3,030,607 MEL'I SPENNENG APPARATUS v Rudolph S; Eloy, Mfiili'gan College, Tenu., assigner to Beannith/Iiils,lncorporated, New York, NY., aic'oiporation of `lisier/v York Filed .Fan..28,\19571,. Ser. No. 636,641 Claims. (Cl. 18--8) The present invention relates to apparatus for the melt Spinning of polyamids such as lnylon 6, nylon 66, etc., polyesters such as Dacro and other organic filamentformingcompositions.

The method of producing synthetic fibers by what is known as the melt spinning process has been practiced commercially for a number of years. In general the method entails pumping a molten filament-forming composition through a downwardly directed. spinneret having from one to several hundred minute orifices, allowing or forcing the newly formed filaments to cool and solidify as'they drop by'gravity for a substantial distance', collecting the filaments into a thread in the cases where' lmore than one orifice is employed and winding the thread into apacka'ge. There is a small amount of drawing'or stretching of the filaments due to their Weight as they fall from the spinneret but` the thread is normally subjected to its main drawing operation subsequent to theinitial packag- While it is desirable to allowA the filaments to' cool gradually during a comparatively longv drop, say fifteen feetormore, from the spinneret` rather than attempt to force the cooling to take place in aIshort distance, hitherto considerable difhculty' has been encountered in maintaininga uniform or constant denier'of the filaments, both in those cases where along drop isemployed andin the case Where cooling is forced to take place during a comparatively short drop. Thisnon-constant or uneven denier is highly objectionable in thatl it affectsthe dyeing characteristics, drawability, etc. of the yarn-or thread@ The uneven denier is caused in--theI cas'eof a long drop of the filaments by air currents which tend to buoy up the extremely light-weight filaments or sway them from a straight-line path so that they do not drop at a: constant rate and consequently do not stretch evenly.,

Another difficulty encounteredA in meltv spinning has been a tendency for the newly formed, filaments to turn back against the lower face of the spinneret and this results at first in uneven -denier and eventually in broken filaments.

It is.th`e general" object of the present invention to provide melt spinning apparatus which produces thread and yarn of constant denier.

It isamore particular object of this invention-'to provide meltspinning `apparatus wherein the newly formed filaments during their free fall from the spinneret are protected from undesirable air currents which would tend to disrupt the free fall of said filaments and consequently produce filaments of non-uniform denier.

It is a further object of the invention to provide melt spinning apparatus wherein the tendency for the newly formed filaments to turn back against the face of the spinneret is substantially reduced.

These and further objects, features and advantages will become apparent as the description of a preferred embodiment of the invention proceeds.

Referring now to the drawings:

FIGURE 1A is an elevational view lof the upper portion of a melt spinning apparatus embodying the invention and showing same housed in a building,

FIGURE 1B is a continuation of FIGURE 1A and shows the lower portion of the apparatus,

FIGURE 2 is a perspective view of an iris diaphragm Federated Mar; i2, 1953 located at the lower end of the apparatusand forming an element of the present invention, v

FIGURE 3' is a sectional view" of the spinneret and shows an iri's diaphragm located closely therebeneath in accordance with the present invention, and

FIGURE 4 isa vertical'n sectional view of the parts shown in FIGURE 2. Y e

The filament-forming composition, such as' a polyamid, polyester, etc'. is contained in molten form in a tank par'- tially indicated at lil, from which it is pumped byAv any suitable means through a` downwardly directed Spinneret y11V, see FIG; 3. The spinneret is' secured in position by nieansof a plate 1'2 whi'chfholds it against 'a vshoulderv 13 provided" in the bottom of the tank 10. With this arrangen-rent the spinneret" may rapidly .be changed to permitthe spinning of threads ofy different denier and having from one to several hundred filaments.

Assho'wn'- in'detail in FIG; 3, a flanged collar member 14islocat`ecl directly beneath the spinneret and i's secured to the bottom of tank" 10 by means of screws 15 which also serve to holdthe' plate 12 in position. An iris diaphragm generally designated 16, of usual` construction, as will be explained later, i's secured by means of screws 1"]v tothe bottom fiange of the' collar member I4. A handle 18 is provided for manual adjustment of the opening through'the'iris diaphragm. Inv FIG. 3, the iris diaphragm is shown' inI its'- fully` openy conditionY but in operation saidf diaphragm isadjusted byV means of the handle 18v so that its central opening is just sufiicientlfy large to accommodate the filaments be-in'gextruded througl'tV the spinner'et'-the` particular adjustment of the diaphragt-n thus depending upon theA arrangement' of the orificesinth'e spinner'ct. The purpose'of the collar member' 1541 and irisdiaphragm- 156" is to-protect the lower'face ofthev spinneret from drafts which would tend to cause the'y newly for-med', stillmolten, filaments to turn back towar'd the' spinneret and Contact the face thereof. This contacting of the face of the spinner'et atfirst causes uneven denier of the filamentsand eventually results in the breakage' thereof.

In` order to give an indication ofthe sizeof the apparatus and? the distance traveled by the fibers after leaving the spinneret,. the'v apparatustis shown-housed:y in a` building generally designated 19' and from FIGS; lA and 1B itwill be seen that the' bottom of the tank 10 isy located approximately' at the ceiling of the second story ofthe building. The'fiberszarei indicated at-Zfland, as shown inIilG.V 1A,J as tlie'newly spun fibers issue from the spinneret and move below' thet iris diaphragm 15 they fall freely from the ceiling: to thev fioo'r of the sec'ondf story, la distance ofalittle less than nine feet. During this initial^drop,fthe fibers pass in front of a fine-meshl screen 2i through-which coolairisblown-to aid the cooling and solidification of the fibers. The fine mesh of the screen 21 prevents the air from striking the fibers with such a great force as to materially divert said fibers from their free verticle fall.

As the fibers approach the oo-r of the second story of the building they enter the top of a vertically arranged tubular inem-ber 22. As shown in FIG. 4, the tubular member 22 has an inner Wall 23 and an outer wall 24 so that at times said member may be heated or cooled by circulating an appropriate me-dium between the two walls, depending upon the type and denier of the yarn being spun. A suitable collecting ring not shown is located in the lower end of the tubular member 22 or just below said tubular member for Ithe purpose of bringing the individual filaments close together into a single strand as is shown emerging from the bottom thereof in FIG. 1B. When the strand leaves the bottom of the tubular mem-ber 22, the filaments have cooled and completely solidified so that the strand is ready to tbe wound into a package and acarreo? thus, as shown diagrammatically in FIG. 1B the strand is passed over a pair of rollers and 26 where a finishing material is applied and -then around a pair of godets 27 and 28 where a very slight amount of stretch is applied and on to a traversing guide 29 and a winding drum 33.

The tubular member 22 is about five feet long and since it extends vertically from the lirst story of the building through the floor of the second story it acts somewhat in e manner of a chimney inasmuch as air tends to flow upward therethrough. The upward movement of air thro-ugh the tubular member is highly undesirable in that such movement of air tends to buoy up the extremely light-weight filaments and prevent the desired uniformi rate of descent and consequent uniform stretching, which as previously mentioned, is necessary if cloth made from the yarn is to have satisfactory dyeing properties. Such air flow may be minimized by having the opening in the bottom of the tubular member as small as possible to accommodate the passage of the filaments therethrough. However the bottom of the tubular member cannot 'be permanently restricted because at the beginning of the spinning operation the filaments must =be threaded through said tubular member. In practice, at the beginning of the operation, the `top of tubular member 22 is closed, as by placing a piece of cardboard or the like over it. As 4the filaments drop into the cardboard from the spinneret, they are allowed to accumulate into la mound or wad until there is a wad of sufficient weight that an yoperator on the second floor of the building can drop the wad through the tubular member to an operator on the first floor who then cuts the wad loose from the oncoming strand and threads said strand over rollers 25 and 26 and the godets 27 and 2S and around a core placed on the winding drum 30.

The present invention provides means for restricting the bottom opening of the tubular member 22 after the wad of filaments has been dropped therethrough and the spinning operation is underway. For this purpose, an iris diaphragm generally designated at 31 and best shown in FGS. 2 and 4 is provided. A flanged collar 32 is welded or otherwise secured to the bottom of tubular member 22 and the iris diaphragm is secured to the flange of said collar by means of screws 33, see FIG; 4.

The iris diaphragm 31 is similar in construction to rthe iris diaphragm 16 and comprises a pair of at rings 34 and 35 having -a plurality of outwardly extending projections 36 and 37 respectively, the projections 37 being thicker than the ring 35 of which they are a part. Rings 34 and 3S are held together by screws 38 which pass through the projections 36 and 37, the thickened projeci tions 37 serving -to space said rings apart. As seen in IFIG. 4, the lower ring 35 is provided with a ilange 39 and the usual array of diaphragm plates 44B and an operating ring 41 are located within the confines of said flange. The plates 4i) are each pivotally connected at one end to the ring 35 as by means of pins 42 shown in FIG. 2 and at their other ends are articulated to the op Clt erating ring 4l. An larm 43 connected to the operating ring 41 extends outwardly therefrom and is provided 'with a handle 41 by means of which the iris diaphragm may be selectively opened and closed. As shown in FiG. 2, a scale 4S is provided to aid the operator in positioning the handle 44 so as to provide the optimum opening of the diaphragm for spinning various types of' yarn. The optimum opening is the one which is just large enough to permit a small amount of lateral movement of the yarn strand and at the same time prevent as much as possible the entry of air -into the bottom of the tube.

Having lthus described a preferred embodiment ot the invention, whatvis claimed is:

l. Apparatus for spinning molten organic filament- 'forming compositions comprising a downwardly directed spinneret through which the molten composition is pumped to form filaments, a collar extending for a short distance below said spinneret, means for adjustably restricting the lower end of said collar, a vertically extending tubular member aligned with said spinneret and said collar whereby the filaments fall by gravity therethrough, and means for adjustably restricting lthe opening in the lower end of said tubular member to a size only suciently large to accommodatethe filaments.

2. Apparatus of claim 1 in which at least one of the adjustable restricting means is a variably settable iris diaphragm.

3. Apparatus of claim 2 having means for indicating the proper iris diaphragm adjustment for different spinning conditions.

4. Apparatus for spinning molten organic filament- Iforming compositions comprising a downwardly directed spinneret through which the molten composition is pumped to form filaments, a collar extending for a shont distance below said spinneret, means for adjustably restricting the lower end of said collar, filament cooling means disposed below said collar, la vertically extending tubular member aligned with said spinneret and said filament cooling means whereby the ilaments fall by gravity therethrough, and means for adjustably restricting the opening in the lower end of said tubular member to a size only suiciently large to accommodate the laments.

5. Apparatus of claim 4 in which at least one of the adjustable restricting means is a variably settable iris diaphragm.

References (Iited in the file of this patent UNITED STATES PATENTS l1,970,384 Mancini Aug. 14, 1934 2,252,684 Babcock Aug. 19, 1941 2,321,336 Tondreau lune 8, 1943 2,404,406 Roddy June 23, 1946 FOREIGN PATENTS v 509,636 Germany Oct. l0, 193() 565,282 Great Britain Nov. 3, 1944 

1. APPARATUS FOR SPINNING MOLTEN ORGANIC FILAMENTFORMING COMPOSITIONS COMPRISING A DOWNWARDLY DIRECTED SPINNERET THROUGH WHICH THE MOLTEN COMPOSITION IS PUMPED TO FORM FILAMENTS, A COLLAR EXTENDING FOR A SHORT DISTANCE BELOW SAID SPINNERET, MEANS FOR ADJUSTABLY RESTRICTING THE LOWER END OF SAID COLLAR, A VERTICALLY EXTENDING TUBULAR MEMBER ALIGNED WITH SAID SPINNERET AND SAID COLLAR WHEREBY THE FILAMENTS FALL BY GRAVITY THERETHROUGH, 